• Volume 72, Issue 2

      August 1970,   pages  47-98

    • A study of brachysclereids in two members of Capparidaceae

      Manju Sharma

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      A study of brachysclereids in two members of Capparidaceae namelyCapparis andCrataeva reveals certain points of taxonomic interest. Three species ofCapparis, i.e.,C. grandis L. F.,C. sepiaria L. F. andC. horrida, and one species ofCrataeva, i.e.,C. religiosa Forst. show some similarities as well as differences in the distribution, structure and ontogeny of sclereids. InCapparis, brachysclereids have a more regular pattern of distribution in the stem and leaves. InCrataeva they are absent in leaves. InCapparis brachysclereids are simple, with very closely lamellated secondary wall devoid of pit-canals. There are some disorganised contents in the lumen. They develop from parenchymatous cells having dense protoplasmic contents which are differentiated as sclereid initials. InCrataeva sclereid initials are large empty cells, produced generally after the activity of secondary cambium has begun. The sclereids are very thick-walled, with numerous pit-canals and no contents. The differences in the sclereid features are helpful in distingishing these two genera.

    • Observations on certain environmental features at the dona paula point in Marmugao Bay, Goa

      Padmakar V Dehadrai

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      The Marmugao Bay, which is an estuary of the river Zuari, showed marked seasonal changes in temperature, pH, salinity, oxygen, turbidity and light penetration. These are largely induced by the south-west monsoon.

      Primary productivity showed a similar seasonal pattern and increased by about two to three times during pre-monsoon and post-monsoon months. Fluctuations in the phytoplankton abundance seem related to the cycle of primary productivity.

      Short-term changes in some of these parameters induced by the tides and day and night conditions were well marked. These are also considerably influenced by the local precipitation and land run-off during south-west monsoon.

    • Changes in the environmental features of the Zuari and Mandovi estuaries in relation to tides

      Padmakar V Dehadrai

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      Changes in the temperature, salinity, pH and dissolved oxygen in relation to tidal rhythm were found to be well marked in the Zuari and Mandovi estuaries. Seasonal differences in the hydrographical factors of the two estuaries are considerably influenced by the south-west monsoon.

      In the Zuari estuary, during the post-monsoon months, almost marine conditions seem to prevail with a little freshwater drainage whereas in the Mandovi estuary the freshwater discharge continues throughout the year which influences the environmental features.

      The two estuaries are rich in inorganic phosphate-P, the source of which in the Zuari estuary appears to be largely from the neritic waters whereas the input of inorganic phosphate-P in the Mandovi estuary seems to be influenced by the river-water.

      The rate of production was high in the samples from the two estuaries during the monsoon month. Changes in the rate of production induced by the tides corresponded with those in the inorganic phosphate-P, chlorophylla and the phytoplankton abundance.

      Probably the flora associated with the lower salinity dominates the crop of phytoplankton throughout the year in the Mandovi estuary whereas in the Zuari estuary the preponderance of the freshwater flora appears only during the monsoon month.

    • Amino-acids and sugars in the exudates from germinating seeds of rice

      K M Leelavathy

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      Substances exuding from rice seeds (Oryza sativa L.) allowed to germinate under aseptic and non-aseptic conditions were examined at different stages during germination (0–120 hrs.). Several strains of indica and japonica rice,viz., Co13, Ptb1, Mtu9, Taiwan 3, TKM6, IR8 and and Adt27 were examined on this count. Leucine, glutamic acid, valine and alanine constituted more than 80% of the total amino-acids exuded out. The three pure line indicas gave out the maximum amounts of amino-acids. Considerable differences in the amino-acid and sugar contents in the exudates were noticed when the seeds were surface-sterilized with mercuric chloride (0·2%). Exudates from surface-sterilized seeds always were richer than the exudates from untreated seeds except in the initial stages. The content of amino-acid and sugar in the former increased with time upto a certain period while there was a progressive decrease in the latter.

    • Epidermal structure and development of stomata in some Polygonaceae

      J A Inamdar

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      In the present paper, epidermal structure and development of stomata are described in 15 species of the Polygonaceae. Epidermal cells ofPolygonum species contain druses of calcium oxalate. Parallel cuticular striations are noticed. Six types of glandular, non-glandular trichomes and extra-floral nectaries are observed. The mature stomata are anisocytic, anomocytic and paracytic. The anisocytic and paracytic stomata may be monocyclic or amphicyclic. The anomocytic stomata are incompletely monocyclic. The increase in number of subsidiary cells in anisocytic and paracytic stomata is due to the divisions of the subsidiaries. The ontogeny of anisocytic and paracytic types is syndetocheilic or mesogenous, while that of anomocytic is haplocheilic or perigenous. Twin stomata are also noticed.


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